Cantilever for near field optical microscopes, plasmon enhanced fluorescence microscope employing the cantilever, and fluorescence detecting method

Abstract

A cantilever for near field optical microscopes is equipped with a probe in the vicinity of a free end thereof. The probe includes a thin film portion constituted by at least one layer of thin film that serves as the surface of the probe, and an inner bulk portion which is covered by the thin film portion. The outermost layer of the thin film portion is a thin dielectric film, and a metal portion is provided toward the interior of the probe from the thin dielectric film.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention is related to a cantilever for near field optical microscopes. The present invention is also related to a fluorescence microscope and a fluorescence detecting method that employ the cantilever. More specifically, the present invention is related to a plasmon enhanced fluorescence microscope and a plasmon enhanced fluorescence detecting method that utilize plasmon enhancement.[0003]2. Description of the Related Art[0004]Near field optical microscopes are optical microscopes that observe, analyze, and process samples with probes in which photons are sealed within regions less than or equal to diffraction limits. Illuminated light is focused into a region of less than or equal to several tens of nanometers by near field probes, and light which is scattered by and which is transmitted through substances present within the region or fluorescence emitted by the substances are detected through a spectrosc...

AI Technical Summary

Benefits of technology

[0010]The present invention has been developed in view of the foregoing circumstances. It is an object of the present invention to provide a cantilever for near field optical microscopes which is capable of effectively utilizing the electric field enhancing effect of plasmon and securing the quantitative properties of fluorescent signals by suppressing metallic light loss. It is another object of the present invention to provide a plasmon enhanced fluorescence microscope and a plasmon enhanced fluorescence detecting method that employ the cantilever.

[0028]the near field light being enhanced by the electric field enhancing effect of the local plasmon.

[0036](B) causing the leading end of the probe of the cantilever for near field optical microscopes defined in claim 1 to approach the detection section, and causing enhanced near field light to be generated at the leading end of the probe;

[0044]In the cantilever for near field optical microscopes, the plasmon enhanced fluorescence microscope, and the plasmon enhanced fluorescence detecting method of the present invention, the metal portion of the probe is coated by the thin dielectric film. Thereby, the distance between the metal portion and the fluorescent labels (fluorescent materials) can be controlled, and metallic light loss of the fluorescence emitted by the fluorescent labels can be suppressed. Accordingly, the electric field enhancing effect of plasmon can be effectively utilized and the quantitative properties of fluorescent signals can be secured.

[0046]Further, measurement can be performed with extremely small amounts of biological samples, which are generally known to be expensive. Therefore, large cost reductions are possible.

Problems solved by technology

Therefore, although Raman spectroscopy is effective for qualitative analysis, expectations cannot be held regarding the quantitative properties thereof.

Further, Raman spectroscopy apparatuses are generally large, expensive, and have poor operability.

However, metallic light loss caused by metal probes is a problem.

Thereby, the energy which is to be utilized to emit fluorescence is reduced, the fluorescence quantum yield of the fluorescent substances decreases, and quantitative properties of fluorescent signals cannot be secured.

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